Loud speaker



Dec. 6, 1927. r 1,651,758.

C. L- FARRAND ET AL LOUD SPEAKER F116;; Nov. 5, 1926 2 Sheets-Shet 1 Q44.) INVENTORS W BYW ATTORNEY$ Dec; 6, 1927-.

c.- L. FARRAND ET A LOUD SPEAKER;

Filed Nov.

5. 1926 z'sh ets-sheg 2.

' M INVENTORS W4 ATTORNEYS &

Fatented Dec; ti, 1927.

CLAIR 'L. FARRAND, FOREST HILLS, NEW! YORK, AND ERNEST ROSS, OF EAST ORANGE, NEW JERSEY; SAID ROSS ASSIGNOR TO FARRAND MFG. CO. INC., OF LONG ISLAND CITY, NEW YORK, A CORPORATION OF NEW JERSEY.

Loon srnaknra.

Application filed November 5, 1926.

This invention relates to loud speakers and more particularly to a clamping ring structure which supports the diaphragm.

' The clamping ring structure forming the subject matter of this application was designed especially'tor use in a loud speaker having a large cone shaped diaphragm, but it may be used with diaphragms of other types. Heretotore in loud speakers of the cone type employing metallic clamping r ngs for the diaphragm it has been necessary to cast the rings or make them-by some such expensive method and it has been necessary to clamp the rings to the edge of the diaphragm by individual fastening devices such as bolts; screws or the like. The main ob ect of this invention is to provide a ring structure so designed that all of its parts may be stamped from sheet metal. A further object of the invention is to provide a ring structure, the rings of which may be interlocked and clamped together by integral portions associated with the ring structure thus eliminating the necessity of employing additional fastening devices. i

The accompanying drawings illustrate a loud speaker of the cone type having a ring structure for the diaphragm construeted'in accordance with the invention.

In the drawings' j Fig. 1 is an elevation of the loud speaker;

Fig. 2 is a side elevation, partly in sectlo on the line 22 of Fig. 1;

Fig. 3 is a partial transverse section through the ring structure taken on the line 33 of Fig. 1; and I Figs. 4 and 5 are detail views showing the rings by themselves.

The particular type of loud speaker shown in the drawings comprises a diaphragm structure which includes a cone 1 and a frustum of a cone 2. The cone and cone frustum are united at their edges and an ornamental cord 3 encircles the diaphragm structure so formed to conceal the joint between the cone and the cone trustum. The other edge of the (one trustum 2 is clamped in the ring structure which forms the subject matter of this invention. The ring structure comprises an inner ring 4 stamped from sheet metal. It is stamped in such a way as to form along Serial No. 146,352.

its inner edge a series of integral tongues 6 (Fig. 5). The ring itructure also comprises an outer ring 7 which is also stamped from sheet metal and so formed as to provide a series of openings 8 located so that their spacing corresponds with the spacing of the tongues 6 on the ring 4 and so that each opening 8 is adapted to receive one of the tongues 6. hen the rings are applied to the diaphragm in the manner hereinafter described, each of the tongues 6 is forced through a corresponding opening 8 in the outer ring 7 and is bent over and against the face of the outer ring to clamp the two rings to the edge portion of the diaphragm as clearly shown in Figs. 1, 2 and 3. The outer ring 7 is also so shaped as to provide a turned over edge portion 9 which forms an annular recess or pocket adapted to receive a ring 10 which is made expansible and contractible by dividing it as at 10 (Fig. 1). This ring may also be a metal stamping. llts purpose is to hold in place a toraminous closure for the central opening in the ring structure. This closure may comprise a ring 11, made of pasteboard or the like, which forms a support for a fabric or screen 12 which extends across the open center of the ring structure. The clamping rings are applied to the cone structure by properly po sitioning them with respect to the edge of the diaphragm and then by suitable me chanical means suchas an automatic machine dcsigned for the purpose, the tongues 6 on the inner ring 4 are forced through the openings 8 and are bent over against the surface of the outer ring 7 in the manner above described. It will be understood that this operation is performed before the expansible ring 10 and'the closure 1112 are in place.

The outer ring 7 is also provided with an upper flange section 18 and a lower flange section 14. By means of these flange sections the ring structure may be attached to a pair of supporting rods 15 by screws 16 passing through openings 17 in the flange sections only one of the rods 15 shows in Fig. 2 as the other is directly behind it in this view. The rods 15 are preferably housed within the cone structure formed by the cone 1 and the cone trustrum 2 and in the finished speaker are concealed by the fabric or screen 12. The rods pass downwardly through an opening 18 (Fig. 1) in the lowermost part of the cone structure and are secured to a supporting base 19 as shown at 20. The particular manner of constructing the supporting base and of attaching the rods to the supporting base forms no part of the present invention but is more fully disclosed incertain other copending applications. The rods 15 also constitutc'a support for an electromagnetic actuating device 21 having an actuating rod 22 connected to the apex of the cone 1v to vibrate the latter in the well known manner.

In practice when assembling loud speakers of the type herein disclosed it has been found more convenient to apply the clamping ring structure to the cone frustum 2 before the cone 'frustum is united with the cone 1. After the complete cone structure is formed with the clamping rings attached to'it, the structure is secured to the rods 15 by means of the screws 16. However, the particular sequence of steps employed in assembling the speaker is immaterial to this invention. One of the last steps in assembling the speaker is the application of the closure 11-12 and of the expansible ring 10 which holds the closure in place. The closure 1l12 abuts against an adja cent surface of the clamping ring 7 as shown in Fig. 3.

' The particular type of speaker disclose in the drawings includes a knob or handle 23 which constitutes convenient means of transporting the loud speaker from one place to another. It may be held. in place by means of a screw M which is inserted through an opening 25 provided in the outer ring 7 before the clamping rings are assembled, the head of the screw being positioned between the two rings and the outer ring being provided with a depression 25 to accommodate the hcadof the screw as shown in Fig. 2. The ring 11 of the closure 1112, as well as the expansible ring 10, should each be provided with an opening that slips over the projecting screw 24 when these parts are assembled. After the closure 11 12 and the expansible ring '10 are positioned in place the knob 23 is threaded'on to the projecting screw 24.

As all of the parts of the ring structure are metal stampings the process of making them is greatly simplified and the cost is considerably reduced. However, the rings are so designed that in spite of their simplicity and inexpensive nature the appear ance of the finished speaker is in no way detrimentally afi'ected. By the use of suitable machinery all of the tongues on one ring may be forced through the corresponding openings in the other ring and bent over in the manner above described. This operation may be more quickly performed than the operation of assembling rings of the cast type, for instance, where the fastening devices have to be individually applied and tightened. The ring structure herein dis closed is of particular value for use in any Certain other details of the loud speaker disclosed but not claimed herein are claimed in other copending applications. The con struction oi the pedestal is claimed in our application, Serial No. 146,353, filed Novemher 5, 1926 and the edge construction oi the diaphragm including the ornamental cord 3 or its equivalent is claimed in an applicatlon filed jointly by ourselves and Paul F. Godley, Serial No. 146,347. The manner oi? supporting the diaphragm structure on the pedestal including the rods 15 passing through the interior ofthe cone structure is claimed in application Serial No. 146,34l8 filed. jointly by ourselves and Paul F. Godley, on November 5, 1926. We claim:

1. In a loud speaker a diaphragm, and a pair of clamping rings between which the edge portion of the diaphragm is clamped,

portions of the other rings to clamp the two rings against theedge portion of the diaphragm.

3. In a loud speaker a diaphragmand a pair of sheet metal clamping rings between which the edge portion-of the diaphragm is clamped, a portion of one of said rings being bentover into engagement with a portion of the other ring to clamp the two rings 1 to the edge portion of the diaphragm.

4:. In a loud speaker a diaphragm. and a pair of sheet metal clamping rings between which the edge portion of the diaphragm is clamped, integral portions of one of said rings being bent over portions of the other ring to clamp the two rings against the edge portion of the diaphra'gi 5. In a loud speaker, a diaphragm and a pair of sheet metal clamping rings between which the edge portion of the diaphragm is clamped, one of said rings having integral portions engaging and interlocked with the other ring to clamp the two rings against the edge portion of the diaphragm.

6. In a loud speaker a diaphragm a pair of rings between which the edge portion of the diaphragm is clamped one of said rings having an inturned edge portion to form an annular seat and an expansible ring held in said sheet.

c 7. Ina. loud speaker a diaphragm, a pair of rings between which the edge portion of the diaphragm is clamped one of said rings a having an inturned edge portion to form an annular seat, a member constituting a tora-minous closure for the open center of the rings and an expansible ring held in said annular seat a ainst said member.

8. In a lou speaker a diaphragm and a 2 clamping ring structure comprising a pair of sheet metal clamping rings interlocked with each other to clamp the edge portion of the diaphragm between them, and a support for the ring structure, one of said rings be- 5 ing provided with integral flanges adapted V to be secured to saidsupport.

In testimony whereof we aflix our signatures.

CLAIR L; FARR ND; ERNEST ROSS. 

